Effects of coral reef habitat degradation and overexploitation on gastropod molluscs at the global centre of marine biodiversity

接下来的50年将是这个星球上生命的关键时期。我们在这段时间内的行动将决定目前正在建立的灭绝浪潮的规模。我们现在所做的，或我们未能做到的，将随着时间的推移而产生共鸣，影响到这个星球上未来的每一个居民。没有其他一代人有这样的责任。珊瑚礁是生物多样性最丰富的海洋生态系统，可以说是受到人类威胁最深的生态系统。在过去的二十年里，珊瑚礁破坏的速度和程度是前所未有的，全球范围内高达20%的珊瑚覆盖面积消失，主要是由于气候变化，过度开发和污染。我们迫切需要了解珊瑚礁退化的过程，以便制定更好地管理珊瑚礁以维持生物多样性的工具和战略。我们建议研究菲律宾的珊瑚礁，因为菲律宾受到异常的人类压力，处于全球珊瑚礁退化的前沿。它也是世界浅水海洋生物多样性中心。那里的珊瑚礁将比其他任何地方失去更多的物种，其中一些可能会灭绝。我们不可能调查所有在那里发现的数千种物种。我们将重点放在蜗牛上。原因如下：（1）这一群体易于普查和测量，（2）与珊瑚和鱼类等群体相比，它在珊瑚礁研究中相对被忽视，（3）软体动物支持许多个体渔民和手工业者的生计，（4）有充分的理由怀疑许多软体动物物种受到过度开发和栖息地退化的威胁，（5）对软体动物渔业或贸易几乎没有管理或监测。菲律宾是世界海洋珍品贸易的中心，那里的开发活动非常激烈。例如，锥螺是生物多样性丧失所造成风险的一个明显例子。它们因其美丽的外壳而备受追捧，并在全球范围内销售数百万。锥螺的损失特别令人关切，因为人们越来越认识到其毒素对医学研究和由此产生的新药和疗法的开发具有潜在的巨大价值。我们将在菲律宾群岛的四个一般地点进行浮潜和珊瑚礁潜水，对蜗牛进行实地调查。选择的地点将代表各种各样的开采强度和珊瑚礁退化阶段。开发强度将通过在每个地点与知识渊博的当地人进行访谈来核实，而珊瑚礁退化的阶段将通过水下采取的珊瑚礁栖息地组成的措施来衡量。将在从浅海近岸礁坪到外礁坡15 m深度的一系列重复断面上对蜗牛进行计数、鉴定，并测量其物种和大小（以衡量种群结构和繁殖状况）。从我们的调查结果，我们的目标是了解这些珊瑚礁的蜗牛损失的速度和顺序，以及它们如何受到身体大小，成熟时的大小，深度范围和贝壳贸易的可取性等因素的影响。这将有助于我们确定菲律宾珊瑚礁和其他地区珊瑚礁对生物多样性丧失的脆弱性。提高我们对珊瑚礁变化的理解将有助于我们制定能够阻止损失的管理战略--我们相信，即使是在世界上人类影响最严重的最没有希望的地区。我们相信，有负担得起和可行的解决珊瑚礁退化的办法。这一试点项目的目的是收集关于菲律宾珊瑚礁软体动物损失的原因和速度的数据。通过我们的外联工作，这项研究以及我们今后将从中开展的研究将有助于使公众关注珊瑚礁退化问题、生物多样性丧失对今世后代的影响以及采取行动改善这一问题的重要性。

The next fifty years will be a critical time for life on this planet. Our actions within this period will set the magnitude of the extinction wave that is presently building. What we do now, or what we fail to do, will resonate through time, affecting every future inhabitant of this planet. No other generation has had such responsibility. Coral reefs are the most biologically diverse of marine ecosystems and are arguably the most deeply threatened by humanity. The rate and extent of reef destruction in the last two decades is unprecedented, with up to 20% of coral cover lost worldwide largely as a result of climate change, overexploitation and pollution. We urgently need to understand the process of reef degradation in order to develop tools and strategy with which to manage reefs better to sustain biodiversity. We propose to study reefs in the Philippines, which is subject to exceptional human pressures and is on the global front line of coral reef degradation. It is also the world centre of shallow water marine biodiversity. Reefs there stand to lose more species than almost any other place, some of them endemics that could go extinct. We cannot survey all of the thousands of species found there. Instead, we will focus on snails. The reasons for this are: (1) the group is easy to census and measure, (2) it has been relatively neglected in reef research compared to groups such as corals and fish, (3) molluscs support livelihoods of many artisanal fishers and craftspeople, (4) there are strong reasons to suspect that many mollusc species are under threat from overexploitation and habitat degradation, (5) there is virtually no management or monitoring of mollusc fisheries or trade. The Philippines is at the centre of the world trade in marine curios and exploitation there is intense. Cone snails for example, represent a clear case of the risks posed by biodiversity loss. They are highly sought after for their beautiful shells and sold by the millions worldwide. Loss of cone snails is of particular concern because of a growing appreciation of the potentially immense value of their toxins for medical research and the development of new drugs and therapies arising from this. We will undertake field surveys of snails by snorkelling and diving on reefs at four general locations throughout the Philippine archipelago. The locations will be chosen to represent a wide range of exploitation intensities and stages of reef degradation. Exploitation intensities will be verified by interviews with knowledgeable locals at each location, while stage of reef degradation will be gauged from measures of reef habitat composition taken underwater. Snails will be counted, identified to species and their sizes measured (to gauge population structure and reproductive status) on a series of replicate transects from the shallow nearshore reef flat to a depth of 15m on the outer reef slope. From our survey results, we aim to understand the rate and sequence of losses of snails from these reefs, and how they are affected by factors such as body size, size at maturity, depth range and desirability for the shell trade. This will help us determine vulnerability to biodiversity loss, both of Philippine reefs, and by extrapolation, those in other regions. Improving our understanding of reef change will help us devise management strategies that can stem the losses - even, we believe, in the most unpromising regions of the world where human impacts are severe. We are convinced there are affordable and feasible solutions to reef degradation. It is the aim of this pilot project to gather data on the causes and rates of loss of molluscs from Philippine reefs. Through our outreach efforts, this study, and future research we will develop from it, will help focus public attention on the problem of coral reef degradation, the consequences of biodiversity loss for today's and future generations, and the importance of action to ameliorate it.